I don't know, we never added any to the sacks or bags when we bagged them. But moisture can be a problem with them I suppose in some places.
Sugar doesn't really burn very well unless it's like falling or floating in the air. then it burns voraciously. The bins are tightly controlled in respect to humidity and temperature. Much more than a grain bin. If grain gets dampened in one it will set up because the grain swells.
Then a person can't get it back out without some seriously dangerous labor. The stuff can't get too dry though either, then it will crack {shatter} and isn't sellable product once damaged.
What could you add to sugar in those little packets that wouldn't interfere with mixing it with your coffee or tea?
Andy